Mourinho paid to underperform at Utd

In a (football) world without enforcement of rules and regulations, could it be possible that the owners of a competing club would offer money via undisclosed channels to a competing manager to maintain a status quo in the club he is managing?

Who would really care? Who would really notice? Who would even think such an absurd thought?

Surely Mourinho would never accept such an offer. And surely nobody would ever make one. But what if...